Adjustable cam track



March 9, 1943. J. w; NEFF I ADJUSTABLE CAM TRACK 2 Sheets-Sheet l IOriginal Filed Feb. 24, 1941 III I II I I I I I I I I L I I IIIIIIIIIIMarch 9, 1943. J, w, NEFF 2,313,477

ADJUSTABLE CAM 'TRA K Original Filed Feb. 24, 1941 2 Sheets-Sheet 2 humnl'ot g QM); 3

Patented Mar. 9, 1943 UNITED STATES PATENT OFFICE Smith Company, of NewJersey New York, N. Y., a corporation Original application February 24,1941, Serial No.

380,373. Divided and 1942, Serial No. 442,244

(Cl. 74-568i 6 Claims.

This invention relates to cams of the track type and has for an objectto provide a cam and follower mechanism in which means are provided foreffecting relative adjustment between the cam and its follower so as toraise or lower the path of reciprocating movement of the follower. Thepresent application is a division of my earlier application, Serial No.380,373, filed February 24, 1941.

More particularly the invention has for an object to provide a cam andfollower adapted to be mounted for relative rotation, the cam having atransversely-inclined eccentric track, and means for effecting lateralmovement between the cam and its follower so as to cause the follower tocontact higher or lower points upon the cam track. t

Another object of my invention is to provide in a cam and followermechanism a pair of cams of the above character having slots definingtransversely inclined endless tracks of corresponding contours openingthrough their opposed faces, a follower bar extending between and havingits ends engaging the pair of tracks, and means for simultaneously anduniformly adjusting the cams toward and from each other to vary theposition of the follower on the sloping tracks and consequently to raiseor lower the path of reciprocating movement of the follower.

Still another object of my invention is to provide a track cam of theabove character comprising a series of arcuate cam sections detachablysecured together to permit the replacement of certain sections as theybecome worn orin order to change the contour of the track.

Other objects and advantages will be apparent from the followingdetailed description of a preferred embodiment of theinvention,jreference being had to the accompanying drawings, in which:

Figure 1 is a longitudinal cross-sectional view through a rotary moldingmachine designed for producing wax crayons and employing a pair ofstationary but laterally adjustable cam rings for actuating thefollowers supporting the rows of plungers associated with the crayonmolds;

Figure 2 shows schematically the sprocketand chain mechanism forsimultaneously adjusting the cam rings toward and from each other;

Figure 3 is a full face view of one of the cam rings;

Figure 4 is a transverse cross-sectional view of the cam ring taken onthe line 44 of Figure 3;

Figure 5 is a transverse cross section'al view this application May 8,

of the cam ring taken on the line 5-5 of Fig. 3;

Figure 6 is a detail view of the outer face of the cam ring showing themanner in which its arcuate sections are held in assembly;

Figure 7 is a transverse cross-sectional view through a cam ring showingone of the cam-adjusting screws;

Figure 8 is a fragmentary face view of a track cam showing thecam-adjusting screw viewed from the left-hand side of Figure 7; and

Figure 9 is a lineal development of the track of the cam of Fig. 3.

In the drawings is illustrated a continuous rotary molding machineadapted for casting sticks of wax crayon, and exemplifying one type ofmachine with which the cam mechanism constituting the subject of thepresent invention may be successfully employed. This machine in generalcomprises a cylindrical mold carrier M supported for rotation onstanchions l and 2, and circumferentially provided with longitudinalrows of radially-disposed tubular molds 3. A pair of stationary trackcams 4 is located adjacent opposite ends of the mold carrier and afollower bar 5 extends between the cams and travels within their tracksduring rotation of the mold carrier. Plungers I0 connected to thefollower bars and slidable within the molds 3 serve to eject the sticksof crayons from the molds in a step-by-step movement. A knife 6 fixed toa support 1 is adjustable circumferentially about the interior of themold carrier so as to trim off the projecting ends of the crayons, thusdetermining the lengths of the crayons finally ejected from the molds.

Projecting circumferentially outward from the mold carrier at itsopposite ends are flanges 8. These flanges are radially slotted atcircumferentially spaced intervals to provide guideways for the followerbars 5. Each follower bar supports the outer ends of a row of plungersl0 associated with a corresponding row of molds on the mold carrier.Upon the ends of the follower bars are rotatably mounted rollers llextending into slots defining endless tracks I2 upon the opposed sidefaces of the cams 4. Each cam is composed of two major parts, a centralcam support i3 and an encircling and laterally shiftable cam ring M.

The tracks l2 of the pair of cams are of a corresponding contour, andthis contour will be determined by the character of the impulses to beimparted to the follower bars and for certain purposes may take the formillustrated in Fig. 3. A lineal development of this cam track is Theeffect of this form of cam upon the plunge ers supported by the followerbars is as follows: During rotation of the mold carrier M throughoutthat part of its circle of travel correspond 5. Likewise the walls ofthe plunger-retracting portion D of the cam tracks leading from. theinnermost to the outermost circular contours of the tracks are madehorizontal.

The transverse slope or pitch of the walls of the tracks of both cams inequal and uniform, and in order to insure the proper operation oftheplungers supported by the follower bars it is necessary that theadjustments of the cams toward and from each other should occursimultaneously and in equal increments of movement so as to maintain thefollower bars horizontal for any position of adjustment of the cams, Toaccomplish this, the inner circumference of ing to the portion A of thecam tracks, the row I of plungers l0 connected to a follower bar aresustained in their fully retracted position. As the follower bar movesthrough an angle corresponding to the portionB of the cam tracks, theplungers are moved radially inward in an interrupted movement so as toprogressively project the cast crayon sticksf from a .row of .molds.Then as the mold carrier moves through the portion C, there is a shortperiod of dwell. Continued movement of the mold carrier through an arccorresponding to theportion D of the cam tracks causes the plungers tobe quickly retracted.

The cam and follower mechanism for accomplishing the above movement ofthe plungers will now be more particularly described. The cam ring M ofeach cam is composed of a plurality of arcuate segments secured togetherin the manner indicated in Fig. 6. Adjacent the ends upon the outer faceof each cam segment (that is, upon its face opposite to that throughwhich the cam' track opens) are upstanding flanges l5 and bolts l6extending through openings in the opposed flanges of abutting segmentsclamp the segments together. By reason of this sectional camconstruction, the cams may be conveniently shipped in knock-downcondition, while worn or damaged sections may be quickly replaced by newones as occasion requires,

The cam tracks l2, at least for the major portion of their length, aredisposed on a slope, as indicated in Fig. 4. That is, the upper andlower walls Ho and HI) of the tracks are transversely inclined so thatwhen the cam rings are shifted toward and from each other, rollers llsupporting the ends of a follower bar 5 are caused to contact higher orlower points upon the sloping tracks. Eachroller is supported on aspindle 9 extending from an end of the follower bar being intermediatelyinclined at approximately the same inclinations as the cam track.

By laterally varying the position of the cams the sequence or pattern ofoperation of the followers, and hence the plungers supported thereby,remains unchanged, although the location of the plungers with respect totheir companion molds for corresponding positions of the .mold carrieris alteredthat is, the working range of the plungers is raised orlowered. In order that the plungers will not be projected beyond theinner ends of the molds in any position of adjustment of the cams, thewalls l2a and H1) of the arcuate portion C of the tracks, representingthe maximum approach. of the rollers toward the axis of rotation of themold carrier, are made horizontal or level, as indicated in Fig.

each cam. ring is notched, as indicated at l8, at angularly spacedintervals (Fig. 3), and fittted within each notch and secured in placeby bolts H! are blocks 20 Figs. 7 and 8) having a screwthreaded,semi-cylindrical recess 2|. The cam support of each cam is likewiseprovided, at points corresponding to the notches I8 on the cam ring,with'clearance recesses 22, in each of which there is rotatably mounteda worm 23 engagingth'e threads of the block 20. Each Worm has a stem 24extending from the clearancenecess to the outer face of the cam and upon.its end is fixed a sprocket 25. As schematically represented in Fig. 2,an endless chain 26 winds over all the series of sprockets 25. Fordriving these chains an operating bar 21 extends horizontally above themachine, and this operating bar carries sprockets 28 which arerespectively connected through chains 29 with sprockets 3B paired withsprockets 25 on two of the stems 24. By connecting a hand-crank K to asquared end of the operating bar, this shaft may be rotated to likewiserotate all the worms 23, through the transmission chains just described,for simultaneously shifting the calm rings toward or from each other.

The function of the cams in the machine just described is as follows:For any fixed position of the cams, the stepped contour of the camtracks allow for the production of only a relatively few selectedlengths of crayons, depending upon the adjustment of the trimming knife.In order to meet the demands of the trade, however, it is desirable thatcrayons should be made accurately to any desired length, withinreasonable limits. For accomplishing this object, the walls of the camtracks 12 are disposed on a slope, as has already been explained, sothat by uniformly and simultaneously adjusting both cams toward or fromeach other, the rollers ll supporting the ends of the follower bars arecaused to engage lower or higher points upon the sloping cam tracks.

For example, when the cams are moved closer together by rotating theoperating bar 21, the rollers contact lower points transversely of thetracks and hence, during rotation of the mold carrier, they follow apath of smaller diameter. As a consequence, the plungers connected tothe follower bars repeat the same pattern or sequence of operations,although their working range is altered with reference to a fixed pointupon the molds (or,.similarly stated, with reference'to the axis ofrotation of the mold carrier). Thus, when the camsare moved closertogether a greater length of crayon is caused to be projected from themolds during the period in which the rollers engaged the stepped portionB of the cam tracks. The machine accordingly is capable of ,producingcrayons. of any desired lengths within its capacity by making a fewsimple adjustments. Because the spindles 9 carrying the rollers areinclined at approximately the same slope as the track, the rollers maypass without obstruction to the full depth of the slots defining thetracks.

While the cam mechanism has been described above in conjunction with acrayon molding machine, this is merely by way of example, and it iscontemplated that the cam mechanism will find useful application inother types of machines in which accurately variable adjustments of thepath of travel of a follower membe is necessary or desirable.

Obviously various changes in the form, construction, arrangement, andcombination of the several parts of my new cam mechanism may be madeandsubstituted for those herein shown and described without departingfrom the nature and principle of my invention as defined by thefollowing claims.

I claim:

1. In a cam and follower mechanism, a pair of cams adapted to bestationarily supported in parallel relation, a pair of slots definingendless cam tracks of corresponding stepped contours opening through theopposed side faces of the cams, a follower extending between said slotsand adapted to travel upon said tracks, said tracks sloping in reversedirections transversely of the cams, and means for simultaneously anduniformly adjusting the cams toward and from each other to raise orlower the position of the follower along the sloping cam tracks.

2. In a cam and follower mechanism, a circular cam support, a cam ringencircling said cam support for shifting movement transversely thereof,a slot defining an endless cam track opening through a side face of saidcam ring, a follower adapted to enter the slot and travel upon saidtrack, said track sloping in a direction transversely of the cam ring,and screw threaded means for shifting the cam ring transversely of thesupport to cause the follower to engage higher or lower points upon thecam track.

3. A cam comprising a circular cam support, a cam ring encircling saidsupport for shifting movement transversely thereof, a slot defining anendless cam track opening through a side face of said cam ring, saidtrack sloping in a direction transversely of the cam ring, and aplurality of screws rotatably mounted upon the support and engaging thecam ring for shifting the cam ring transversely of the support.

4. A cam comprising a circular cam support, a cam ring encircling saidsupport for shifting movement transversely thereof, a slot defining anendless cam track opening through a side face of said cam ring, saidtrack sloping in a direction transversely of the cam ring, a pluralityof screws rotatably mounted upon the support and threadedly engaging thecam ring, and an operating member connected to all of said screws forsimultaneously rotating the screws for shifting the cam ringtransversely of the support.

5. A cam comprising a .circular cam support,

a cam ring encircling said support for shifting movement transverselythereof, a slot defining an endless cam track opening through a sideface of said cam ring, said track sloping in a direction transversely ofthe cam ring, a plurality of screws rotatably mounted upon the supportand threadedly engaging the cam ring, sprockets associated with saidscrews, a chain extending between the sprockets, and a manual operatingmember for moving the chain to simultaneously shift the cam ringtransversely of the support.

-6. A cam comprising a circular cam support, a cam ring encircling saidsupport for shifting movement transversely thereod, said cam ring beingcomposed of a plurality of arcuate sections detachably connectedtogether, a slot defining an endless cam track opening through a sideface of said cam ring, said track being sloped in a directiontransversely of the cam ring, and a plurality of screws rotatablymounted upon the support and engaging the cam ring for shifting the camring transversely of the support.

JOHN W. NEFF.

